This invention relates generally to an accurate, movable and easily transportable system for distance measurement and geologic mapping in subterranean shafts. Accurate, dependable measurement of bearings and directions and stereophotography are required for geologic mapping in subterranean shafts, such as, for example, nuclear waste storage investigations. Subterranean sites presently being investigated are in rock with natural magnetism and also contain steel structures. These factors preclude the use of devices that rely on the earth's magnetic field for a reference direction, that is, a magnetic compass. Under these conditions, a surveyed reference (strike rail), is necessary with all directions or bearings related to the reference.
Utilizing a conventional strike rail is time consuming and therefore extremely expensive. Previous methods consisted of obtaining bearings or directions from surveyed rails that had to be pre-positioned around the periphery of the work platform. This method is not compatible with a galloway. Magnetic compasses have been used but are not dependable. Photography for geologic photography can be obtained by hand, holding the camera, or by using a conventional tripod. These methods are not suitable in this case because of the speed and precision requirements.